Human cognition and exploration on the ocean can be traced back to the 3rd century BC and experienced three processes, i.e., pure commerce & adventure sailing, sailing comprising science meanings and pure scientific expedition based on modern technology. The oceanography is a science based on observation and every leap in the process of cognition on the ocean is based on the advent of a new observation method and measuring instrument. Recalling the history of ocean observations, the advent of the acoustic Doppler current profiler enabled the people to master large-scale circulation structure around the globe, the emergence of the conductivity-temperature-depth (CTD) profiler enabled the people to ascertain the large-scale water mass formation and transformation in the entire ocean, the launch of various satellite altimeters enabled the people to make preliminary cognition on meso-scale and small-scale processes in the ocean such as spatial structure and time evolution of meso-scale eddies and internal waves.
The oceanographic study has made great progress in large-scale and meso-scale processes but scientific study on microscale has just begun. In recent years, the shear, temperature, conductivity probes with high-frequency sampling have been successfully developed in succession, opening the curtain for the study on ocean microscale process. Currently, the measurement methods of ocean microstructure mainly include mooring point measurement method and shipboard vertical profile measurement method. The mooring point measurement method only conducts measurement at a specific depth at a particular fixed position in the ocean, can get better time-series observations but fails to obtain the vertical structure features of the ocean microstructure. The shipboard vertical profile measurement method completes measurements of the ocean microstructures from the surface to a depth by means of an oceanographic vessel, but fails to get the temporal variability of ocean microstructure and is restricted by unfavorable factors such as complicated sea conditions and site operations. For the study on ocean microstructure, time variance and spatial structure are important parameters, based on this, it is urgent to solve the problem of the development and obtainment of an ocean microstructure observation instrument for both vertical spatial structure and time variance.
For the description or the study of ocean microstructure, the turbulent kinetic energy dissipation rate is an important physical variable. Therefore, the direct and accurate measurement is significant to improve the study on turbulent kinetic energy transfer and dissipation. In recent years, the shear probe with high-frequency sampling has been capable of accurately measuring the turbulence kinetic energy dissipation rate, but its application is either based on mooring point measurement or based on shipboard vertical profile measurement and fails to integrate both two measurements. It can be seen that it is of significance to create an innovative method and observation platform to achieve organic integration of the shear probes with high-frequency sampling into both platforms so as to break through the bottleneck of ocean microstructure observation.